LONDON (AP) — British ex-Foreign Secretary Boris Johnson has slammed Prime Minister Theresa May's Brexit policy, a move likely to fuel speculation that he is seeking to oust her.

Johnson wrote in the Daily Telegraph on Monday that May's so-called Chequers plan for continued ties with the European Union after Brexit will leave Britain in a weakened position.

He said that May is giving EU leaders a "victory" without even trying to forge a Brexit plan that would strengthen Britain's hand after it leaves the EU in March.

He said that Britain has "gone into battle with the white flag fluttering over our leading tank."

May's government is involved in delicate negotiations with EU leaders about Britain's future relationship with Europe.

Johnson resigned as foreign secretary in July to protest May's Brexit policy.